Concerns have been expressed over the frequent occurrence of accidental needle-stick or needle-prick injuries by health care providers because, even though disease from such injuries is rare, there is always the possiblity that such a disease might be transmitted and be lethal. It has been established that the risk of acquiring hepatitis B from accidental injury involving HBsAg-positive blood is 26% and that the risk of transmission of acquired immune deficiency syndrome is somewhat less than that. A. D. Nixon et al, The Lancet, pp. 888-9, Apr. 9, 1986.
It is now known that a substantial proportion of needle-stick injuries occur when a hypodermic needle is being recapped or resheathed. Center for Disease Control guidelines recommend that needles never be recapped and that all used needle/syringe assemblies be discarded into disposal units. In practice, such guidelines are often disregarded in the complex and busy hospital environment, creating the further risk of possible re-use of discarded syringes and needles by drug abusers.
While efforts have been made to develop simple, inexpensive, and convenient devices for reducing the dangers posed by used syringe assemblies, it appears that the use of such protective devices has presented, to a greater or lesser extent, the same risks involved in the recapping of used needles. Examples of such devices may be found in U.S. Pat. Nos. 2,270,536, 3,712,302, 4,273,123, 3,796,359, 3,820,852, 4,592,744, 4,332,323, 3,944,069, and 4,182,448. The problem of reducing the dangers of accidental needle sticking while disposing of used hypodermic needles is specifically addressed in U.S. Pat. Nos. 4,573,975, 4,610,667, and 4,596,562, but such devices all require axial or endwise movement of a used, unsheathed needle toward a receiving target supported by the user's other hand, to that extent, a significant risk remains.
An important aspect of this invention therefore lies in providing a relatively simple and inexpensive device that may be easily handled by a user to encase a used syringe and needle assembly and, in particular, that may be manipulated in use without requiring any endwise movement of the needle tip towards a user's hand. The device may be stored in flat condition and is readily foldable so that, for example, several such devices may be easily carried in a user's pocket prior to use. Despite its deformability, the device includes a portion that takes on increased stiffness when folded in use. That portion defines a tough, protective enclosure for the needle tip, and the needle is prevented from escaping from such enclosure because of the adhesive seal between folded wall portions of the device and between those wall portions and syringe itself. Once enclosed within the folded device, a syringe may be safely discarded with the tip of the needle effectively shielded to avoid injury.
Briefly, the device takes the form of a pad of soft, foldable sheet material, preferably an easily-deformable, fluid-impermeable material such as a closed-cell plastic foam, having upper and lower surfaces and having a pair of lateral sections disposed on opposite sides of the pad's longitudinal midline. A coating of pressure-sensitive adhesive extends over the upper surface, and a protective shield or patch of tough, flexible, imperforate sheet material is secured to a relatively small area of that upper surface. Ideally, the shield has a pre-formed crease aligned with the midline of the pad. In use, the barrel of a used syringe is shifted laterally into contact with the adhesive coating and is adhered to that coating to immobilize the syringe on the pad with the needle tip overlying the protective shield. Thereafter, the pad and shield are folded to encase the needle tip between adjacent side sections of the shield and to urge portions of the adhesive-coated surface of the pad into sealing contact with each other about the syringe and about the periphery of the folded shield. At no time during such immobilizing and folding operations does endwise movement of the needle tip towards a user's hand become necessary; the syringe assembly may be shifted by lateral movement into its secured position on the pad, and the folding operations only require finger movements in directions transverse to the axis of the syringe. Although the thin protective shield is readily folded along its crease line, once that step has occurred the fold performs a stiffening or reinforcing function that enhances the protective action of the shield. Such reinforcement, along with the extensive areas of adhesive contact between the folded side portions of the pad, and between those portions and the syringe itself, effectively prevent escape or protrusion of the needle tip from its containment.
Other advantages, features, and objects of the invention will become apparent from the specification and drawings.